﻿<?xml version="1.0" encoding="utf-8" ?>
<root>
  <express name="add">
    <left>5</left>
    <right>10</right>
    <result>15</result>
  </express>
  <express name="minus">
    <left>21</left>
    <right>10</right>
    <result>11</result>
  </express>
</root>
